Conventional safety light curtains have been used to guard avenues of access to machines or processes requiring limited access. This limited access may be for the purpose of industrial safety or for preventing contamination of materials or devices being used, as well as for other reasons. By way of example, an industrial hydraulic press or stamping machine might include one or more safety light curtains to prevent the machine from operating when any object is within a specified distance of the machine. Some such machines may have multiple points of access and it is desirable to provide an integrated system to protect all of these points of access.
Conventional safety light curtains are often connected together to provide an integrated protection system, but these configurations often suffer from increased response time as more curtains or larger curtains with more individual optical elements are chained together. This is due to the fact that conventional safety light curtain systems are configured to uniquely address each optical element within each light curtain individually and sequentially. It is desirable to improve these known safety light curtains so that multiple safety light curtains may be connected together without adversely impacting the response time.
When connecting together multiple safety light curtains, conventional units may require different units for use as a starting or master unit, a middle unit or an end or terminal unit with an installation of multiple units. Installation, configuration and maintenance of conventional units may also require the use of an external programming device such as a personal computer. It is desirable that safety light curtains include improved configuration tools and greater flexibility of use.